Photographic enlarging apparatus.



M. SOHfTTZE.

PHOTOGRAPHIG BNLARGING APPARATUS.

APPLICATION I ILED OOTQ23, 1905.

Patented Jan. 19, 1909.

2 SHEETS-SHEBT 1.

h i'lzzesses:

M. SGHI ITZE.

PHOTOGRAPHIG ENLARGING APPARATUS.

APPLICATION FILED OCT. 23, 1905.

Pawnted Jan. 19, 1909.

2 BHIEETSr-SHEET 2.

mz nT W..U w. H 5 X A Pdi't ovnegs.

UNITED STATES; PATENT OFFICE.

I MAX i rnorosumw saunsme arraaa'rus.

Specification of Patent.

Patented Jan. 19, 1909.

Application filed oaths; as, 1905. Serial no. 288,901;

To all whom it may concern:

Be it known that I, Som'irzma citizen of Germany, residing at Berlin SW. 11, Konlggratzerstrasse 105, Germany, have invente a new and useful Improvement in Photographic -Enlarging Apparatus; and I do hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to improvements in photographic enlarging apparatus whereby the determination of the right time of exposure is facilitated.

In enlarging negatives by day-light it is usual to determine the-right time of exposure by a previous trial ex osure and develo ment of small strips of romida er. This method is inconvenient and unre 'a le, as the testing strips must be put in and taken out in the darkeroons and in the case of appara? 5 shmild tus it t d r slid s in ol es therepes eil Hir to a d he o he w le m te i and moreover the developing of the 'numerL- ous testing strips is troublesome and causes loss of time, and the day-light may have entirely changed during the removal and develo ment of the testing strips, whereby all that as been determined is rendered useless.

The resent enlarging ap aratus obviates these isadyant .a resu t which is substgntgsll realize by the arrangement in the 51 e V tsipparatus between the negative s 'r r lv 6 l o g t-t ght s able slide, ch n l s he ligh i e pou e t e determ ned y of s ma l h t m r e mea u em t efi ted i ..e mwhs b r o th appar tus t esesstivehas be d ly Pl eed- Ai -t n s ty of the li ht which. reaches the sensitized layer in e back-chamber vof the apparatus is always proportional to the intensit. of the light falling in the fore-chamber o the a paratus on to the photometer, no matter w ether the day-1i ht be powerful or slight and the negative w ich. is to be enlarged be thick or thin, it is only necessary that the manufacturer of the a paratus should ascertain once for all the egree indicated by the photometer with the proper exposure, and the person using the apparatus only needs to expose the sensitive layer under the negative to the day-light until this degree of the photometer is attained'in order always toohtain suitable exposure of the sensit ve layer with other intensity of day-light and any .01; or negatives.

.By suitable determination of the diaphragm openin and the employment of a photometer of t e right kind and proper sensibility, and its suitable arran ement. in the apparatus, etc. the period 0 photometric measurement may be made to agree exactly with the right time of exposure. If the photometer be then placed outside the active rays, that is to say the rays of light by means of which'the enlargement is effected, the photometrlc measurement and the enlargement can be efiected simultaneously, whereby the operator not only saves time butis independent of the changes in the intensity of the day-light, as every change acts in precisely the same manner on the photometer and on the sensitive layer. 1

After each enlargement the photometer may be removed from the apparatus. It is p ef r h wever, that. the Photemetsr erpara ua atsldam act ve rays .o'iilight.

The 1 last form e p mete is that of a small box with an opening in the end for the introduction of the photometer paper and a second opening in the top for exposin the 1photometer paper. The box is arrange in t e fore-chamber of the apparatus outside the activerays in such a manner that the 0 ening in its and lies on theslide in e sid 0 he pparatus, 0 t a he Ph tometer aper can 0 put into the box from .011 0.

fi-it be d s re to p oy s e erbs o sensitive material of .difierent degrees of sensitiveness in the same apparatus for produci nsen argem n ens a adj a le pparatus of @fifierent ratios of enlargement, the apparatus must be provided with several diaphragms with openings of different widths or with one ad'ustable diaphragm, similar to that on the 0 jeotive of the photographic cameras, or slides made of more or less transparent material can be pushed in overthe photometer aper, for the purpose of enaling the rig t time of exposure to be hotometrically determined for each sort of tive layer or for each ratio of enlargement.

In the accompanying drawings a form of the invention is shown by way of example.

Figure 1 shows a vertical section of the apparatus; Fig. 2 an enlargod'verticajl sefltiQn of the up r part of the apparatus.

The en arging apparatus consists as usual sensi- ,rieraandt e the box d.

tive on to the copy carrier 0, on which the sensitive layer (for exam 1e a plate or paper coated with bromid of s ver)' is fixed.

In the ap aratus between the negative carlens b, outside the active rays of light (shown in dotted lines), a small pasteboard box (1 is arrangedone (right) end of which is pasted into an o eriing in the 'side wall of the apparatus. '1 e left end of the box (1 has a small opening i, in the top. A small stri of photometer paper e is pushed into the ox when the apparatus is used. The bottom of the box is covered with velvet or plush k for the purpose of preventing light from entering directly through the box into the apparatus. A slide it can be pushed into the box, in order to close the openin i dur-' ing the removal and examination of t e strip e. Or the left wall of the apparatus can be provided with an opening into which a paste oard Z covered with velvet or plush m is pasted and into which, during the examination of the stri e, a slide is pushed, until it closes the who e opening over the lens I). For the usual work, however, the slides 71. and can be dispensed with, the velvet or plush in the box (I preventing in a suflicient degree Y the entrance of the light through the box into the apparatus, even after the removal of the strip a. The diaphragm g of the lens is so adjusted that the sensitive la er is accurately exposed, when there is a s i ht darkening of the photometer paper 6 be ow the exposure opening in the box. The slide it may also be made of moreor less trans arent material (for exam le white or colored silkpaper, gelatin, ce uloid or the like) and be employed for exactly adfiusting the right time or exposure, especia y when difierent sorts of sensitive layers are employed.

The ap aratus is used in the followin manner: he negative that is to be enlarge is placed in the negative carrier 0 and the bromid paper or the like fixed on the copy carrier 0 in the dark-room. At the same time a fresh stri of the photometer paper e (for example ce oidin paper) is introduced into The apparatus is then so placed thatthe day-light can enter. From time to time the strip of the paper a is drawn out and examined to see whether the necessary dark tone has appeared in the part which lay below the opening'in the top ofthe box. When the dark tone is attained, the exposure is discontinued, the development efiected and the enlargement fixed in the usual manner.

it the ap aratus be adjustably arranged for the amp oyment oiseveral sorts of'sensitive material of "difl erent degrees of sensitiveness (for example bromid aper and plates covered with rornid of s' ver) or for the production of different ratios of enlargemerit, it is necessary as a matter of course betere the enlargement is taken to take that diaphra or to push in'that slide which be terial and ratio of enlargement.

aphic ne ative's on paper, the sli e k can the opening '5.

roduced on a very sensitive lass plate or m, it is sometimes better to c ose the opening i by means of the slide h during the inspect-ion of the strilp'c, because, otherwise, a httle day-light cou pass through the box d in spite of, the velvet it, while the paper strip 0 is removed therefrom. This light would be reflected to the inner surface of the a paratus and of the negative and from here t rough the lens I) to the sensitive glass plate or film fixed on the copy carrier 0, where it would produce dark s ts or clouds.

I am well aware t t enlarging cameras .and photometers and actinometers are already known. My invention, however, consists not'in the mere juxtapositiomor aggregation of both devices, but in an-im roved enlargingpamera provided with 1; sm opening, in t e side-wall between the negative carrier and the lens, through which opening the photometer pa er can be introduced into the apparatus. T e use of an actinolneter in the common way is very tedious, because the ne atives to be enlarged have not the same arkness, and darker or denser negatives require a l0nger exposure in the enlarging camera than clearer or lighter negatives. Thus, the time of exposure must be determined for each special negative by means of the photometer and 0 trial exposures, before the enlarging process can begin. Therefore photometers were hitherto not used for enlarging purposes. With my improved enlarging camera, these tedious trial exposures are dispensed with, because Thus, a darker, the sensitive longs to the employed kind of sensitive ma- For the usual work, is. enlargin photo- I action of the day-light upon the actinometer.

Having thus described my invention what I claim as such and desire to secure by Letters Patent isr I 1. Photographic enlarging apparatus, consisting of a negative carrier, 8. copy carrier, a lens situated between the negative carrier and the copy carrier, and walls made of light-tight material and provided with an openingbetween the negative carrier and the lens support for insertion of actinometer paper into the apparatus.

2 Photographic enlarging apparatus, consistmg of a ne ative carrier, a copy carrier, a lens situated etween the negative 6811161 and the copy carrier, walls made of lighttight material and provided with an opening between the negative carrier andthe lens support, for insertion of actinometer paper into the apparatus, and a diaphragm to control the proper exposure of sensitivematerial 5 upon the copy carrier.

3. Photographic enlarging apparatus, consisting of a ne ative carrier, a copy carrier, a lens situated tween the negative carrier and the copy carrier, and rovided with a 10, diaphragm, and walls ma e of light-tight material and provided with a light-tight closable opemng, between the negative carrier and the lens support, for insertion of actinometer papfir into the apparatus.

15 4. Photograp 'c enlarging apparatus, consist' of a ne ative carrier, a copy carrier, a lens situated tween the negative carrier and the copy carrier and provided with a diaphragm, a device between the negative 2o carrier and the lens support and to the one side of the lens, having an opening for exposingthe actinometer paper and light-tight I actinometer paper by rays coming through 30 I the negative and simultaneously with t printing of the picture.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

I SOHUTZE.

' Witnesses:

HENRY HASPER,

WoLnEMaB HAUPT. 

